List all three-digit numbers using only the digits 2, 4, and 6.
, ⊃ ∘.+/ ⊖ ↓ (10 * ⍳3) ∘.× 2 4 6
222 224 226 242 244 246 262 264 266 422 424 426 442 444 446 462…
Find the sum of the digits of each of the first 1000 numbers.
, ⊃ ∘.+/ 3 ⍴ ⊂ ⍳10
0 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 10 2 3 4 5 6 7 8 9 10 11 3…
List the numbers with three or fewer digits in base 3, none of which are 1.
, ⊃ ∘.+/ ⊖ ↓ (3 * ⍳3) ∘.× 0 2
0 2 6 8 18 20 24 26
(⍳3*3) ∊ , ⊃ ∘.+/ ⊖ ↓ (3 * ⍳3) ∘.× 0 2
1 0 1 0 0 0 1 0 1 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 1 0 1